We were discussing the conversion of Varsinentals yesterday at my LBS. There was a group of us and we all agreed a Varsinental Monster Truck is a valid build. I've seen one posted by JJ Pistols and a handful of others. I dig your ride and certainly if I do a Monster Truck build it'll have 26" wheels and (at least) a front hub brake.

If I had a crankset lying around in mind I'd probably do it. Cartridge BBs can be had pretty cheap and I don't think those conversion kits are very expensive either.

What size are those tires? Where is the tightest spot for 26" tires? If I built one I'd like Fat Franks.